Conventional temperature sensors in this technical field are disclosed in the following Patent Documents 1 and 2, for example. In the temperature sensors described in these publications, a bottomed tubular holder made of brass containing a glass-sealed thermistor (temperature detecting device) is filled with a resin, so as to prevent water from entering the temperature detecting device part. Respective one end parts of leads are connected to the temperature detecting device of such a temperature sensor, whereas the other end parts are connected to an electrode pair extending to the outside of the resin. A pair of leads for transmitting signals detected by the temperature detecting device to a control processor are connected to the electrode pair.
The inventors advanced studies concerning temperature sensors which do not necessitate an electrode pair which is a part with a high possibility of short-circuiting and, as a result, have completed a prototype of temperature sensor 50 as shown in FIG. 15. FIG. 15 is a schematic sectional view showing a prototype of temperature sensor (not publicly known). As shown in FIG. 15, a temperature detecting device 56 having a pair of leads 54A, 54B connected thereto is disposed at a bottom part of a bottomed tubular holder 52 made of a metal in the temperature sensor 50, whereas the holder 52 is filled with a resin 58. The resin 58 filling the holder 52 forms a cylindrical side wall 62 on the opening 60 side of the holder 52. The side wall 62 constructed by the resin is formed with a hole 64 through which the leads penetrate, whereas the leads 54A, 54B drawn out of the resin 58 are bent and taken out by way of the hole 64.
A lead drawing member 66 having a part buried in the side wall 62 is attached to the outside of the hole 64 formed in the side wall 62. The lead drawing member 66 is a tubular elastic body and restrains the leads 54A, 54B from bending in excess in the vicinity of the hole 64. Such a lead drawing member 66 prevents the leads 54A, 54B from bending by an angle near 90 degrees and breaking in the vicinity of the hole 64, which is a part where the leads 54A, 54B are likely to bend greatly in a part from which the leads 54A, 54B are taken out.
The inside of the side wall 62 formed by the resin 58 is filled with a resin 68 so as to bury the leads 54A, 54B. This prevents water from entering from the interface between the resin 58 and the leads 54A, 54B, and secures and protects the leads 54A, 54B. A waterproof cap 70 covers the resin 68 and side wall 62. The waterproof cap 70 covers the upper part of the temperature sensor exposed to an environment incurring water droplets and steam, and thus prevents water droplets and the like from entering the inside of the sensor 50 from boundaries of the members and reaching the temperature detecting device 56. Here, numeral 72 refers to a metal stay, insert-molded with the resin 58, for supporting the leads from the lower side and suppressing their movement, whereas numeral 74 refers to a protective tube for preventing the metal stay 72 from damaging the leads 54A, 54B.
Patent Document 1: Japanese Patent Application Laid-Open No. HEI 11-23379
Patent Document 2: Japanese Utility Model Application Laid-Open No. HEI 5-3955
Patent Document 3: Japanese Patent Application Laid-Open No. 2002-267540
Patent Document 4: Japanese Utility Model Application Laid-Open No. HEI 6-62336
Patent Document 5: Japanese Patent Application Laid-Open No. HEI 8-128901